Exhaust valves

S

S1jor

New member
Hi,

My exhaust valves don’t appear to be working on my 2016 v6s.
The light on the exhaust button comes on when it should.
I can move the valves with my hands fairly easily.
Fuse 43 is in and not blown.
The vacuum lines look like there all
Connected
Is it likely the vacuum pump has gone?
Is there a way of testing the pump, or is there anything else I have missed checking??

Thanks

Simon
 
Hi,

You should be able to moved the valve actuators\mechanisms by hand quite easily to ensure they're not seized. Very close to where the vacuum lines connect.
 
That's good.

Then I'd suggest disconnecting the vacuum hoses (just pull off) and tie wrap a balloon on. See if it blows up when the car is idling\revving, it may even pop depending on the pressure it can generate.

Then you know if the compressors are working or not. If the valves are working, then it has to be that. If I recall correctly, there's a T-piece on the vacuum hose, could just one side be disconnected?
 
Hmm, I’d assumed cause its called vacuum pump, they sucked to close the exhaust valves?? Not blew??
 
You may not even have a vacuum pump as there was a bulletin/recall to replace them. Mine was done years ago foc. Thereafter and on later models it just took a feed from the inlet manifold.
…and yes of course it’s a vacuum not a compressor.. if running you’ll hear it high up behind the passenger seat in the corner
 
If it’s been replaced, what am
I looking for??,
Would they have taken the vacuum pump away or just disconnected it?? And if that’s happened, vacuum pipes running from the exhaust valves all the way to the inlet manifold??
Sorry for all the questions
 
S1jor said:
If it’s been replaced, what am
I looking for??,
Would they have taken the vacuum pump away or just disconnected it?? And if that’s happened, vacuum pipes running from the exhaust valves all the way to the inlet manifold??
Sorry for all the questions
Click to expand...


Your 2016 V6S doesn’t have the old style active exhaust vacuum pump and reservoir.

Instead, the vacuum pipe runs from the upper rear of the engine compartment, along the fuel lines on the underside of the car, into the rear left wheel arch behind the NVH pad (noise/vibration/harshness), and into the vacuum hose on the active exhaust operating valve.

This link shows the active exhaust vacuum line for the 3.0L and 5.0L cars.... https://parts.jaguarlandroverclassic.com/parts/index/part/id/C72.C7230.C7230251.C723025110341/brand/jaguar/

I've attached the Jaguar Technical Bulletin dated 03/02/2015 which shows how the vacuum conversion was done on earlier cars. In it, Service Instruction ‘A’ is for the 3.0L V6 and Service Instruction ‘B’ is for the 5.0L V8.
 

Attachments

Are you up to date with software updates, if you had them done your valves will not open until 1500 to 2000rpm. I can not remember the numbers but if you search out my previous threads it will explain all.
 
There are two software H139 & H239 they came about a year apart. Avoid H139 means our car will not remember dynamic mode when ignition turn off.. H239 reduces noise even further by using electronic wizardry... hence my 400 has no updates after H139..
 
Is there a way to check what software updates have been done? I’m convinced my 400 has been neutered (doesn’t remember Dynamic mode on start up) but my dealership are adamant that it’s not had either of the software updates?
 
A pointer, I’ve instructed my local main JLR dealer to put a note on my vehicles service record that instructs them to ask me first before any software updates are installed - I absolutely do not want my V6S noise neutered at all!!
 
The valves don’t seem to be moving at all,
I think from what I have read, with the engine off the valves are open (loud), upon start up the valves are open , until the vacuum closes them?? Is that correct??
I’ve been under the car and had someone start it, and they don’t seem to move

I have another look at the vacuum lines and make sure there all connected
 
Given you know the valves work smoothly, then I would take the pipe off one side and see if it is creating a suction. That will get you one step closer to deciding if it’s a mechanical (vacuum) or electrical/switching issue
 
cj10jeeper said:
Given you know the valves work smoothly, then I would take the pipe off one side and see if it is creating a suction. That will get you one step closer to deciding if it’s a mechanical (vacuum) or electrical/switching issue
Click to expand...


I would also think that the active exhaust vacuum pipes suck rather than blow air but this early F-Type ‘Active Exhaust Vacuum Control Diagram’ (which is prior to the vacuum conversion) seems to show the air flow going into the exhaust valves?

This is what it says about the ‘Air flow check valve’ and ‘Air flow restrictor’ shown on the diagram.....

“In the pipes between the solenoid valve and the exhaust valves, a restrictor is installed in parallel with a check valve. The restrictor slows the flow of air through the pipes, to damp the opening of the exhaust valves. The check valve ensures that air flows only through the restrictor when the exhaust valves are opened, but allows the restrictor to be by-passed when the exhaust valves are closed, to give an undamped closing movement.”

I suppose the only way to be sure is to remove the vacuum pipe from a working exhaust valve to check if it’s sucking or blowing air?
 

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RPSN said:
cj10jeeper said:
Given you know the valves work smoothly, then I would take the pipe off one side and see if it is creating a suction. That will get you one step closer to deciding if it’s a mechanical (vacuum) or electrical/switching issue
Click to expand...


I would also think that the active exhaust vacuum pipes suck rather than blow air but this early F-Type ‘Active Exhaust Vacuum Control Diagram’ (which is prior to the vacuum conversion) seems to show the air flow going into the exhaust valves?
Click to expand...

It's 100% certain to be a vacuum. Given the conversion is to take a feed from the inlet manifold which has a vacuum in it, not a positive pressure
 
cj10jeeper said:
RPSN said:
cj10jeeper said:
Given you know the valves work smoothly, then I would take the pipe off one side and see if it is creating a suction. That will get you one step closer to deciding if it’s a mechanical (vacuum) or electrical/switching issue
Click to expand...


I would also think that the active exhaust vacuum pipes suck rather than blow air but this early F-Type ‘Active Exhaust Vacuum Control Diagram’ (which is prior to the vacuum conversion) seems to show the air flow going into the exhaust valves?
Click to expand...

It's 100% certain to be a vacuum. Given the conversion is to take a feed from the inlet manifold which has a vacuum in it, not a positive pressure
Click to expand...


I would think so.

However, the earlier set-up was also operated by a vacuum as shown in the diagram I posted, which seems to show the air flow going into the exhaust valves?

To be 100% certain, the vacuum pipe that connects directly to the exhaust valves would need to be removed and checked.
 
RPSN said:
cj10jeeper said:
RPSN said:
I would also think that the active exhaust vacuum pipes suck rather than blow air but this early F-Type ‘Active Exhaust Vacuum Control Diagram’ (which is prior to the vacuum conversion) seems to show the air flow going into the exhaust valves?
Click to expand...

It's 100% certain to be a vacuum. Given the conversion is to take a feed from the inlet manifold which has a vacuum in it, not a positive pressure
Click to expand...


I would think so.

However, the earlier set-up was also operated by a vacuum as shown in the diagram I posted, which seems to show the air flow going into the exhaust valves?

To be 100% certain, the vacuum pipe that connects directly to the exhaust valves would need to be removed and checked.
Click to expand...

My read of that diagram is clear
The vacuum pump creates a partial vacuum and that is stored in the reservoir. The suction applied to the exhaust valves goes through a damper, which will be there to smooth the process so the valves open progressively and not in a jerk motion as the pump works. To close the valves air enters the pipework through a filter and valve which is undamped and thus allows the valves to close rapidly. If not then when closing you'd have to wait ages for the vacuum to decay by leakage. Air flow is bi directional in the pipe depending upon the desire to open or close.

Later cars simply eliminated the vacuum pump and reservoir [noisy and unreliable] with a straight vacuum from the inlet manifold
 
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